UX-13 P4: the setup wizard for installers

The Setup tab draws the Installer view's page model one step at a time,
from each field's `wizard` step in app/uilayout.py: meter (with the kettle
test), inverters and batteries, solar (optional), prices, peak limit
(battery modes: "comes in a later update", OPT-11), check and start.
It reuses P2's controls and saves through /config/validate and
/config/save. No route was added.

- First run: /config/model says `setup_needed` when the stored options name
  no power request entity, or on a new install (no `setup_done` and no
  `auto` in the Store, control not started). The page opens #setup only
  when opened with no route. The wizard's save writes `setup_done`.
- Kettle test: GET ha/entities?entity= reads one entity now, in W. The
  change decides: up keeps meter_invert off, down turns it on; a net or
  import/export meter that goes down blocks the step with what to check.
- Last step: validate.setup_checks() beside the refusals: the meter reads,
  each power request entity exists in HA (bad if not, SAFETY-77), battery
  levels and power with direction, solar sign, prices. Saves with
  shadow_mode on by default, then a confirmed restart naming the 0 W.
- P2 test finding (a): a stale save lists only the keys the other surface
  moved (the blob handed out on open, by fingerprint, against stored now).
- test_setup.py; tools/ux13_wizard_blobs.py makes the 88 blobs the wizard
  can save; all accepted by Supervisor 2026.08.0 AppOptions (offline).
- DECISIONS/UX-13-setup-wizard.md; DOCS "Setup, for a new install".

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LyR88rXETvwhTgx6yHE39p

goodwe_controller/app/static/app.css

@@ -216,3 +216,11 @@ input:disabled{opacity:.6}
 #savebar .btn.primary{background:var(--accent);border-color:var(--accent);color:var(--on-accent)}
 @media (max-width:640px){#savebar{bottom:62px}}
 #s-set{padding-bottom:80px}
+/* UX-13 P4: the setup wizard */
+.steps{display:flex;gap:4px;margin:4px 0 12px}
+.steps i{flex:1;height:6px;border-radius:3px;background:var(--track)}
+.steps i.done{background:var(--accent)} .steps i.cur{background:var(--accent);opacity:.55}
+.msg.ok{background:var(--ok-bg);color:var(--ok)}
+.sev.bad{background:var(--bad-bg);color:var(--bad)} .sev.warn{background:var(--warn-bg);color:var(--warn)}
+.checklist li{display:flex;gap:8px;align-items:flex-start;overflow-wrap:anywhere}
+.kettle .row{margin-top:8px}